This invention relates to lid closure devices for vessels and more particularly, vessels which operate either under negative or positive pressure.
Typical closure devices for vessels are described in Canadian Patent 319,521 and U.S. Pat. Nos. 3,144,165; 3,310,329; 4,347,944 and 5,193,864.
U.S. Pat. No. 3,077,360 describes a bolted clam shell type closure device for a pressurized vessel lid. Two hemispherical shaped bands are drawn together to clamp machined wedge-shaped perimeter ledges together to seal the lid to the vessel. U.S. Pat. No. 4,288,001 also discloses separable circular shaped bands where hydraulic cylinders are used to draw the bands together to effect a clamping action of the lid to a vessel. The bands include a channel which fit over machined vessel and lid ledges to clamp the lid to the vessel. U.S. Pat. No. 3,235,124 describes a closure system which rotates a plurality of wedges by use of a perimeter ring to engage the vessel wall and seal the lid to the vessel.
In addition to the circular clam shell type closure devices, there are the standard swing bolt or through bolt clamping designs for securing the lid to the vessel. Although these closure designs work very well they are subject to misalignment and distortion due to uneven tightening of the bolts and hence are inherently slow to open and close.
These various lid closure designs suffer from a host of drawbacks including complex designs for the closure, intensive fabrication techniques to achieve proper seal, heavy components which are bulky and awkward to handle and detract from quick release, custom designs for each vessel diameter and little, if any, accommodation in respect of tolerances in fabrication. An object of an aspect of this invention is to provide a quick release closure which is particularly suited to positive and negative pressure vessels and particular high pressure vessels for containing liquids.
In accordance with an aspect of this invention, a quick release closure system is provided for securing a lid to a vessel. The quick release system comprises a plurality of evenly spaced apart periphery located lugs secured to the vessel lid and vessel wall where respective sets of lugs opposed one another. A corresponding plurality of clamping blocks are carrier on a ring which encompasses the perimeter of the lid and vessel where the ring is drawn inwardly to force the clamp blocks onto the lugs to effect closure of the lid on the vessel.
According to an aspect of the invention, a pressurized vessel having a quick release lid closure system for clamping a vessel lid to a vessel container,
i) the lid having about its perimeter a plurality of circumferentially spaced apart lid lugs, the container having about its opening perimeter a corresponding number of opposing circumferentially spaced apart container lugs, the lid lugs and container lugs defining sets of opposing lugs, the opposing lugs having sloped faces which define a truncated wedge narrowing outwardly from the vessel, the wedge having a gap defined between the opposing lid lugs and container lugs, a compression seal provided between the lid and container for sealing the vessel when the lid is closed;
ii) the closure system comprises an open hoop with spaced apart ends, the hoop carrying a plurality of spaced apart clamp blocks corresponding in number to the plurality of lug sets, each said clamp block having a truncated wedge shaped channel for mating engagement with the truncated wedge of a corresponding lug set;
iii) means for pulling the spaced apart hoop ends towards one another to reduce the circumference of the hoop to move the clamp blocks onto corresponding said wedges and by virtue of the mating engagement of the clamp blocks with the wedges, drawing the opposing lugs together to close the gap and to seal the lid to the container by compressing the compression seal.
According to another aspect of the invention, a pressurized vessel having a quick release lid closure system for clamping a vessel lid to a vessel container,
i) the vessel lid and/or the vessel container having a plurality of spaced apart first components of the lid closure system;
ii) a hoop positioned about the vessel and located opposite the first components of the lid closure system, the hoop carrying a corresponding plurality of a second component of the lid closure system, the plurality of the second components being aligned with the first components, the hoop having spaced apart ends;
iii) means for pulling said hoop spaced apart ends towards one another to move said second components onto said first components to an extent which clamps said lid to said container, said pulling of said hoop ends towards one another exerting an inwardly radially directed force of said second components on said first components; and
wherein said first component is a lug provided on said lid and said second component is a swing lug pivotally mounted on said vessel, said hoop carrying said swing lugs to pivot them towards and move said lid lugs to draw said lid closed on said container when said means pulls said hoop ends towards one another.